Hoist.



PATBNTED MAY 9, 1905.

R. GONRADER.

HOIST.

APPLICATION HLBD'MAB. 16,1901.

No. 789,206.- PATBNTED MAY 9, 1905.

R. CONRADER.

HOIST.

APPLICATION FILED MAB. 16,1901..

2 SHEETS-SHEET 2.

Y Eatented May 9, 1905.

PATENT CEEICE.

RUDOLPH CONRADER, OF ERIE, PENSYLVANIA.

Ho|sT.

SPECIFICATION forming part of Letters Patent N0. 789,206, dated May 9,1905.

Application filed March 16, 1901. Serial No. 51,546.

T0 all wil/0772, it may concern:

Be it known that 1, RUDOLPH CONRADER, a citizen of the United States,residing at Erie, in the county of Erie and State of Pennsylvania, haveinvented certain new and useful Improvements in Hoists; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as'will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to hoists; and it consists in certainimprovements in the construction thereof, as will be hereinafter fullydescribed, and pointed out in the claims.

This invention is illustrated in the accompanying drawings, as follows:Figure l shows a section on the line 1 1 in Fig. 3. Fig. 2 is a sectionon the line 2 2 in Fig. 3, the piston being omitted and viewed in thesame direction as in Fig. l. Fig. 3 showsa bottom view of the device,the valve being in section. Fig. 4 shows a side view of thecontrolling-valve. Fig. 5 shows a section on the line 5 5 in Fig. 4.Fig. 6 shows a section of the valve on the line 6 6 in Fig. 4.

A A marks the working cylinder. This may be made of drawn tubing. It isprovided with the cap A/ and is screwed into the head C.

The piston B is arranged to operate in the working cylinder. 1tcomprises the main head I), having the perforations b, the leather cupwith its expanding-ring b3, and a back plate for supporting the cup b2.The piston-rod B is screwed into the head and plate b4 and extendsthrough the stuflingbox C5. The usual swiveled ring B2 is secured to theend of the piston-rod. Extending through the rod is the passage b5. Thisis normally closed by the cock Zz. The purpose of this passage is todraw off any oil that may leal; by the piston.

The cylinder C surrounds the cylinder A and forms an oil-reservoir.' Itis provided with the heads C and C2. A passage c leads from the cylinderC to the bottom of cylinder A. This passage is controlled by the valveC3, so that any size opening may be given the passagev desired. Thecapacity' of the cylinder C is preferably suicient to hold enough oil tofill the cylinder A, so that the piston B may be subjected only toliquid under pressure. The upper end of the cylinder C is provided withthe usual ring C", by which it may be suspended.

The hoist is designed to operate as follows: Air is admitted above theoil in the cylinder C. This forces the oil through the passage c. Theopening in the passage is proportioned to effect as slow a movement asdesired. The oil acting on the piston lifts the ring B2 and itsload.When the desired lift is accomplished, the air-supply is shut off, andif it is desired that the hoist remain stationary` for any length oftime it may be locked by closing the valve C3. When the piston islowered, the'air is allowed to exhaust from the cylinder C. 1nstead ofgoing to the atmosphere, however, it is carried to the upper end of thecylinder A and there confined. It will readily be seen that the pressureof the exhaust-air above the piston is added to the load on the piston,so that a given downward movement of the piston is effected with a muchsmaller exhaust movement of air from the cylinder C than would be thecase were the exhaust immedi-` ately to the atmosphere, and the ai'rremaining in the cylinder C is therefore left at much higher pressurethan as if the exhaust were direct to the atmosphere. l/Vhen anotherlift is desired from the hoist, the air is allowed to exhaust from thecylinder A to the atmosphere and a fresh supply is admitted to thecylinder C. While the exhaust from the cylinder A and turning in of thesupply to the cylinder' C should be practically simultaneous, an exhaustmovement should preferably slightly precede the other in order that nounnecessary pressure need be exerted in the cylinder C.

Bearing in mind the operation of the device, the mechanism foraccomplishing it can be readily understood. The air-supply pipe D entersthe controlling-valve E, and the air passing through this valve iscarried by the pipe F to the top of the cylinder C. A pipe G carries theexhaust from the cylinder (l, by way of the valve Evand pipe Gr, to thetop of the cylinder A. This pipe also carries the vexhaust from the topof the cylinder A, by

way of the valve E, to the atmosphere. The

part e2, and thence through the port f' and passage f into the pipe F.At the same tirnev y the air is passing from the pipe G, through'passage e, to the atmosphere.

the passage g, port g', part es, port e', and

With this position of the valve the h oist is lifting. When it isdesired to lower, the valve is given a quarter-turn to the left. Thiswill cut off the passage of the air through the port f from the part e2and will bring the port e into register with the passage lg and the portf3 into register with a by-pass f2, leading from the passage f. Thiswill also cut oil' the part e3 from the passage e and the atmosphere.Air will then pass from the cylinder C, by the pipe F, passage f,by-passf2, port f3, part e3, port e, passage g, and pipe G, into the topof cylinder A. `The downward movement of the piston takes place as soonas the air-pressure above the piston and the load or the hoist is equalto the pressure below the piston. The speed of this downward movementmay be regulated by the size of the opening through the valve G3.

This construction results in several marked improvements, among' whichmay be stated: By confining the exhaust against the lifting pressure fora downward movement of the hoist the volume of air for the ordinaryoperation ofthe hoist is much reduced. It will be noted also that no airpasses from the shop into the cylinder A, the valve E opening thecylinder A to the atmosphere only with an exhaust movement of air fromthe cylinder A. Another advantage of this construction lies in'thepossibility where a check-valve D' (or other valve) in the supply-pipeis provided of disconnecting the supply-pipe after a lift, running thehoist to another position, lowering the work, and then again lifting theparts after letting go of a part of the load. This is especiallyvaluable for use in foundries,

` when a pot of molten iron may be lifted, carried to the mold, loweredand poured, and then the pot again lifted for the return movement. Theoil forms an intermediate liquid-piston against which it iscomparatively easy to keep the working piston tight. It also forms amedium by which a 'dash-pot effect is given to the movement of the hoistand also a ine-'- dium by means of whichA the hoist maybe instantly andpositively locked inanyposition. The oil also lubricates all the workingparts perfectly. By placing the reservoir-cylinder around the workingcylinder and constructing the hoist so that this outside cylinder bearsthe lifting strainv very light metal may be used for the workingcylinder', ordinary drawn brass tubing answering the purpose very well.It will be noted that the plungercup b2 is pressed into engagement withthe walls of this cylinder A by the spring 3 and that the spring b3 isheld in place by the supports formed at both sides of the spring by thehead L. The outer flange of the head I) is beveled, and the cup also isbeveled, so that the edge of the head engages the head of the cup andprevents the curling in of the cup.

What I claim as new is- 1. In a hoist, the combination of a liftingmeans; means for supplying fluid-pressure to said means; means forconfining the entire exhaust fluid from the lifting side of the hoist toexert a counter-pressure against the lifting pressure during a loweringmovement; and a valve mechanism for 'controlling the supply fluid andthe passage of fluid fromthe lifting to the counter-pressure side of thehoist, said valve mechanism being arranged to cut O the supply whileconnecting the lifting and counter-pressure sides of the hoist and formaintaining the connection between the lifting and counter-pressuresides of the hoist during the entire lowering movement.

2. In a hoist, the combination of a lifting means; means for supplyingfluid-pressure to said means; means for confining the exhaust fluid fromthe lifting side of the hoist to exert a counter-pressure against thelifting pressure during a lowering movement; means for exhausting theconfined counter-pressure fluid during a supply movement of theliftingfluid; and a valve mechanism for controlling the supply fluid,the passage of fluid from the lifting side of the hoist to thecounter-pressure side and the exhaust of fluid from the counter-pressureside,said valve mechanism being arranged to cut offl the supply whileconnecting the lifting and counter-pressure sides of the hoist tomaintain a connection between the lifting and counter-pressure sides ofthe hoist during the entire lowering movement and to close saidconnection during asupply movement of fluid.

3. In a hoist, the combination of a lifting means; means for supplyingfluid-pressure to said means; means for confining the exhaust liuid fromthe lifting side of the hoist to exert a counter-pressure against thelifting pressure during alowering movement; means for exhausting theconfined counter-pressure fluid during a supply movement of the liftingfluid;

a valve mechanism for controlling the supply fluid, the passage'of fluidfrom the lifting side of thehoist to the counter-pressure side and theexhaust of Huid from the counter-pressure side, said valve'mechanismbeing arrangedv to cut off the supply while connecting the lifting andcounter-pressure sides of the hoist to maintain'a connectionbetween thelifting and coun- IIO ter-pressure sides of the'hoist during the' entirelowering movement and to close said connection during a supply movementof fluid; and to open the counter-pressure side to the exhaust during asupply movement.V

4. In a hoist, the'combination of a lifting means; means for supplyingHuid-pressure to said means; means for confining the exhaust fiuid fromthe lifting side of the hoist to exert a counter-pressure against thelifting pressure during a lowering movement; and a valve mechanismcomprising a single valve element for controlling the supply fiuid andthe passage of fluid lfrom the lifting to the counter-pressure side ofthe hoist, said valve mechanism being arranged to cut off the supplywhile connecting the lifting and counter-pressure sides of the hoist andto maintain a connection between the lifting and counter-pressure sidesof the hoist during the entire lowering movement.

. 5. In a hoist. the vcombination of a lifting means; means forsupplying Huid-pressure to said means; meansfor confining the exhaustfluid from the lifting side of the hoist to exert a counter-pressureagainst a lifting pressure during a lowering movement; means forexhausting the confined counter-pressure fiuid during a supply movementof the liftingfluid; and a valve mechanism comprising a single valveelement for-controlling the supply fiuid, and the passage of fluid fromthe lifting side to the counter-pressure side, said valve mechanismbeing arranged to cut off the supply while connecting thelifting andcounter-pressure sides 'of the hoist to maintain a connection betweenthe lifting and counter-pressure sides of the hoist during the entirelowering movement and to close said connection during a supply movementof fluid.

6. In a hoist, the combination of a lifting means; means for supplyingfluid-pressure to said means; means for confining the exhaust fiuid fromthe lifting side of the hoist to exert a counter-pressure against thelifting pressure 'during a lowering' movement; means for f exhaustlngthe confined counter-pressure Huid during asupply movement of theliftingfiuid; a valve mechanism comprising a'single valve element forcontrolling the supply Huid, the passage of fluid from the lifting sideof the hoist to the counter-pressure side and the exhaust of Huid fromthe counter-,pressure side, said valve mechanism being arranged to cutoff the supply while connecting'the lifting and counter-pressure sidesof the hoist to maintain a connection between the lifting andcounter-pressure sides of the hoist during the entire lowering movementand to close said connection during a supply movement of fluid; and toopen the counter-pressureside to the exhaust during a supply movement.

7. In a hoist, the combination with a cylinder having a piston travelingtherein; of a valve device for controlling the admission into thecylinder, on one side of the piston', and forv controlling the releaseof such pressure; and a pipe conducting the whole exhaust of the valveto the cylinder on the other side of the piston, which last-mentionedportion of the cylinder is entirely closed against theentrance oftheordinary outside air.

8. In a hoist, the combination with a cylinder having a piston travelingtherein; of a valve device for-controlling the admission,into

the cylinder, on one side of the piston; of al fresh supply ofHuid-pressure at each lifting operation of the piston and forcontrolling the 'release of such pressure; and a pipe conducting thewhole exhaust of the valve to thel cyllinder on the other side of thepiston, which last-mentioned portion of the cylinder is entirely closedagainst the entrance of the ordinary outside air.

9. In a hoist, the combination with a cylinder having a piston travelingtherein; of a valve device for controlling the admission into thecylinder, on one side of the piston and for controlling the release ofsuch pressure; and vapipe conducting the whole exhaust of the valve tothe cylinder on the other side of the piston, which last-mentionedportion of the cylinder is entirely closed against the entrance lof theordinary outside air and arranged to confine said exhaust to form acounter-pressure on the piston.

10. In a hoist, the .combination with a cyl- 'inder having a pistontraveling therein; of a vvalve device for controlling the admission into'the cylinder, on one side of the piston and for controlling the releaseof such pressure; and a pipe conducting the whole exhaustv of thevalve-tothe cylinder on the other side of the ipiston, whichlast-mentioned portion of the cylinderis Ventirely closed against theentrance Lof the ordinary outside air and arranged to lconfine saidexhaust to form a counter-pressure on the piston, the said valve devicebeing arranged 'to control the exhaust therefrom.`

11. In a hoist, the combination with a cylinder having a pistontraveling therein; of a valve device for controlling the admission intothe cylinder, on one side of the piston; fresh supply of Huid-pressureat each lifting operation of the piston and for controlling the releaseof such pressure; and a pipe conducting the whole exhaust of the valveto the cylinder on the other side of the piston,.which lastmentionedportion of the cylinder is entirely closed against the entrance of theordinary outside lair and arranged to confine said exhaust to formacounter-pressure on the piston.

12. In a hoist, the combination of a lifting means; means forsupplyingthefluid-pressure to said means;.means for confining theexhaust fluid from the lifting sidel of the hoist` to exert acounter-pressure against the lifting pressure duringalowering movement;means ,for exhausting the confined counter-pressure IOO IIO

uid during a supply movement of the lifting fluid; and a valve mechanismfor controlling the supply iiuid, the passage of Huid from the liftingside of the hoist to the counter-pressure side and the exhaust of iuidfrom the counter-pressure side, said valve mechanism being arranged tocut o the supply while connecting the lifting and counter-pressure sidesof the hoist to maintain a connection between the lifting andcounter-pressure sides of the hoist during the entire lowering movementto close said connection during a supply movement of fluid, and to openthe exhaust from said counter-pressure side and to close the supplyduring said exhaust movement.

13. In a hoist, the combination of the cylinder; a piston in saidcylinder; a sing le valve; a pipe or passage leading from said valve tosaid cylinder below said piston; a pipe or passage leading from saidvalve to the upper end of the cylinder; a supply pipe or passage leadingto said valve, said valve being arranged to control the supply and theexhaust from the upper end of the cylinder; and the connection betweenthe ends of the cylinder.

' 14. In a hoist, the combination of the cylinder; a piston in saidcylinder; a valve; a pipe or passage leading from said valve to saidcylinder below said piston; a pipe or passage leading from said valve tothe upper end of the cylinder; a supply pipe or passage leading to saidvalve, said valve being arranged to control the supply and the exhaustfrom the upper end of the cylinder, and the connection between the endsof the cylinder, the arrangement of the valve being to close the supplyand exhaust during a connection between the ends of the cylinder and tomaintain a connection between the ends of the cylinder during the entire"lowering movement.

15. In a hoist, the combination of the cylinder; a piston in saidlj'cylinder; a valve; a pipe or passage leading from said valve to saidcylinder below said piston; a pipe or passage leading irom said valve tothe upper end of the cylinder; a supply pipe or passage leading to saidvalve, said valve being arranged to control the supply to and exhaustfrom the said cylinder, and the connection between the ends of thecylinder, the arrangement of the valve being to close the supply andexhaust during a connection between the ends or' the cylinder, tomaintain a connection between the ends of the cylinder during the entirelowering movement and to open the exhaustduring the supply.

16.- In a hoist, vthe combination of the cylinder; a piston in saidcylinder; a valve; a pipe or passage leading from said valve to saidcylinder below said piston; a pipe or passage leading from said valve tothe upper end of the cylinder; a supply pipe or passage leading to saidvalve, said valve being arranged to control the supply to and exhaustfrom the said cylinder, the connection between the ends of the cylinder;and means for closing the supply-passage during the exhaust.

17. In a hoist, the combination of the cylinder; a piston in 4'saidcylinder; .a valve; a pipe or passage leading from said valve to saidcylinder below said piston; a pipe or passage leading from said valve tothe upper end of the cylinder; a supply pipe or passage leading to saidvalve, said valve being arranged to control the supply of the exhaustfrom the upper end of the cylinder; the connection between the ends ofthe cylinder, the arrangement of the valve being to close the supply andexhaust during a connection between the ends of the cylinder, and to open the exhaust during the supply; and means for closing thesupply-passage during the opening of ,thel exhaust.

18. In a hoist, the combination of the cylinder; a piston `in saidcylinder; a valve; a pipe or passage leading from said valve to saidcylinder below said piston; a pipe or passage leading from said valve tothe upper end of the cylinder; a supply pipe or passage leading to saidvalve, said valve being arranged to control the supply of the exhaustfrom the upper end of the cylinder; the connection between the ends of'the cylinder, the arrangement of the Valve being to close the supply andexhaust during a connection between the ends of the cylinder; and thevalve, D, in the supply-pipe.

19. In a hoist, the combination of the cylinder; a piston in saidcylinder; a valve; a pipe or passage leading from said valve to saidcylinder below said piston; a pipe or passage leading from said Valve tothe upper end of the cylinder; a supply pipe or passage leading to saidvalve, said valve being arranged to control the supply to theexhaustfrom the upper end of the cylinder; and the connection between the endsof the cylinder, said valve comprising the body having the passage 0l,f,

f2, g and e, and the valve proper having the parts e2 and @3, and portsCZ, f, f3, g and e.

20. In a hoist, the combination of the working cylinder; a secondcylinder surrounding the working cylinder; said outside cylinder beingHuid-tight; means for supply connections with said outside cylinder; areduced passage connecting said cylinders; a piston in said workingcylind er; a piston-rod extending therefrom; and a drain-passageextending through said piston and piston-rod.

21. In a hoist, the combination of the working cylinder, A; the piston,B, therein; the rod, B, extending therefrom; the cylinder, C,surrounding the cylinder, A; the passage, c, l,between the cylinders;the valve, C3, controlling said passage; the supply, D; the valve, D',therein; the pipe, F, leading within and to the top of the cylinder, C;the pipe, G, leading within the cylinder, C, to the top of the cylinder,A; the valve, E, comprising thel -bod E having the passage, d,connecting IOO with the supply-pipe, D; the passage, f, and In testimonywhereof Iaix my signature in;

by-pass, f2, connected with the pipe F; th: presence of two witnesses.

passage, g, connected with the pipe, G, an

the passage, e; the single valve proper' or ele- RUDOLPH CONRADER' ment,E2, having the two parts, e2 and e3, and Witnesses:

the ports, d', f', f3, g and e; the said outer H. C. LORD,

cylinder being arranged to bear the load. R.` F. LANZA

